Posts Tagged ‘capacitors’
Are We Prepared for a Catastrophic Solar Storm?
A solar disaster isn't a question of if, but when--and it looks like soon
Curious about what a CME would mean for us?
Within weeks, backup generators at nuclear power plants would have run down, and the electric pumps that supply water to cooling ponds, where radioactive spent fuel rods are stored, would shut off. Multiple meltdowns would ensue. “Imagine 30 Chernobyls across the U.S.,” says electrical engineer John Kappenman, an expert on the grid’s vulnerability to space weather. A CME big enough to take out a chunk of the grid is what scientists and insurers call a high-consequence, low-frequency event. Many space-weather scientists say the Earth is due for one soon. Although CMEs can strike anytime, they are closely correlated to highs in the 11-year sunspot cycle. The current cycle will peak in July 2013.
The most powerful CME in recorded history occurred during a solar cycle with a peak similar to the one scientists are predicting in 2013. During the so-called Carrington Event in 1859, electrical discharges in the U.S. shocked telegraph operators and set their machines on fire. A CME in 1921 disrupted radio across the East Coast and telephone operations in most of Europe. In a 2008 National Academy of Sciences report, scientists estimated that a 1921-level storm could knock out 350 transformers on the American grid, leaving 130 million people without electricity. Replacing broken transformers would take a long time because most require up to two years to manufacture.
"We need to build protection against 100-year solar storms."Once outside power is lost, nuclear plants have diesel generators that can pump water to spent-fuel cooling pools for up to 30 days. The extent of the meltdown threat is well-documented. A month before the Fukushima plant in Japan went offline in March, the Foundation for Resilient Societies, a committee of engineers, filed a petition with the U.S. Nuclear Regulatory Commission recommending the augmentation of nuclear plants’ emergency backup systems. The petition claims that a severe solar storm would be far worse than a 9.0-magnitude quake and could leave about two thirds of the country’s nuclear plants without power for one to two years.
Preventing a surge from a CME would be costly. With enough warning (at least a few hours, probably), power companies could shut transformers off entirely, turning them back on after the storm. But shutting down the grid on such a large scale would cost billions. To confidently do so, forecasting must be accurate.
Last October, NASA scientists announced its Solar Shield program to monitor solar eruptions and predict storms. Though a good step, the system uses a satellite that was launched in 1997 and designed to run just five years. No other country has anything similar, or as advanced.
Our backup systems aren’t in place yet, either. The Department of Homeland Security is funding the development of an emergency replacement transformer, but it won’t be field-ready for several years. Kappenman has developed a $100,000 capacitor to block storm-induced surges, but these are unproven in emergency situations. “A massive solar storm is a ‘low probability’ event the same way a 100-year flood is,” Thomas Popik, the author of the NRC petition, says. “Just as we build levees to protect against 100-year floods, we need to build protection against 100-year solar storms.”
When The Sun Unleashed Its Plasma Blast This Week, Earth Got Lucky
What a predicted 2013 blast from the sun could mean for the U.S.
to see what a CME would do to Earth.
And click to see the amazing video of this week's massive solar belch.
Micro-Supercapacitors Could Boost Lifetime of Portable Devices
The new micro-supercapacitors have at least double the energy storage density of the best supercapacitors
Batteries can store electrical energy in chemical reactants and typically have higher energy storage densities than supercapacitors. But supercapacitors simply store energy as electrical charge and can endure a charge-discharge cycle millions of times, compared to just several thousand cycles for batteries.
"We have known for some time that supercapacitors are faster and longer-lasting alternatives to conventional batteries, so we decided to see if it would be possible to incorporate them into microelectronic devices and if there would be any advantage to doing so," said Yury Gogotsi, a materials engineer at Drexel University in Philadelphia.
Gogotsi worked with John Chmiola, a chemist at the Lawrence Berkeley National Laboratory. They etched electrodes made of monolithic carbon film into a conducting substrate of titanium carbide, and created micro-supercapacitors with an energy storage density at least twice as much as existing supercapacitors.
That suggests micro-supercapacitors can more efficiently store energy within ever-smaller physical spaces. By directly integrating the supercapacitors with the devices they power, researchers can boost the density of microelectronic devices and allow for more functionality, less complexity and enhanced redundancy.
The almost infinite cycle life of micro-supercapacitors would make them ideal for capturing and storing energy from renewable resources, and for on-chip operations to make electronic devices longer lasting, according to Chmiola.
More short-term applications would likely combine micro-supercapacitors with micro-batteries for the most possible energy storage. But the researchers eventually hope to boost super-capacitor storage to levels closer to batteries, and hold onto the supercapacitor edge regarding charge-discharge cycles. The looks bright indeed -- and we can think of a which could use more juice while doing recon.
[via ]